英语翻译The difficulty in object indexing is to determine the id

英语翻译
The difficulty in object indexing is to determine the identity of an object under arbitrary viewing conditions in the presence of cluttered real-world scenes or occlusions.Local characterization has shown to be well adapted to this problem.The small size of the characteristic regions makes them robust against occlusion and background changes.To obtain robustness to changes of viewing conditions they should also be invariant to image transformations.Recent methods for indexing differ in the type of invariants used.Rotation invariants have been presented by [10],rotation and scale invariants by and affine invariants by.
Schmid and Mohr [10] extract a set of interest points and characterize each of the points by rotationally invariant descriptors which are combinations of Gaussian derivatives.Robustness to scale changes is obtained by computing Gaussian derivatives at several scales.Lowe extends
these ideas to scale invariance by maximizing the output of difference-of-Gaussian filters in scale-space.Tuytelaars et al.[13] have developed affine invariant descriptors by searching for affine invariant regions and describing them by color invariants.To find these regions they simultaneously use interest points and contours.Instead of using an initial set of features,Chomat et al.select the appropriate scale for every point in the image and compute descriptors at these scales.An object is represented by the set of these descriptors.All of the above methods are limited to a scale factorof2.

对象索引的困难是确定物体的身份在任意的浏览状态存在的情况下真实场景杂乱或遮挡.当地的表征表明要适应这一问题.较小尺寸的特点使他们对闭塞地区的鲁棒性和背景的变化.得到鲁棒性的浏览状态的变化,他们也应该不变图像变换.最近为索引方法不同的类型的不变量使用.提出了旋转不变性的旋转和尺度不变性和仿射不变的.
麦斯莫尔提取兴趣点和确定集的每一分结合旋转不变量描述符的高斯衍生物.规模变化的鲁棒性得到高斯衍生金融工具计算几个尺度上.
这些观念尺度不变性最大的输出滤波器.吴昱已经开发出仿射不变量的仿射不变量的描述符通过搜索区域和描述的颜色不变量.他们发现这些地区同时使用兴趣点和轮廓.而不是使用一个初始的功能集,王汝成等选择适当的比例为每一点的图像描述符计算,这些鳞片.一个对象代表的是套这种描述符.上述所有方法限于规模.